Battery Power from the Sun
If you have a much-loved classic car, you probably have it stored in a garage somewhere, or under a car cover that protects it from the weather, preserving its paint job, precious rubber hoses and moving parts, and above all, the battery. Because when you’re ready to go stylin’ down the boulevard, the last thing you want is a dead battery. You want to turn that key and hear all that horsepower roaring to life, not the sad grinding and slowly dying sound that signals that you are not going anywhere today.
All you can do then is make a trip to the auto parts store and get yourself another battery, replace it and then haul your old battery back down to the store for recycling. Better to keep that battery charged.
You may wonder how your battery went dead in the first place. For that, you have to understand something about how a battery produces electricity. Batteries are constructed of lead plates, distilled water, and sulfuric acid. The water and acid create an electrolyte solution, and the electrons in the solution move back and forth connecting with the lead plates and that produces electricity.
When a battery sits idle for a long time, this solution (which is very volatile and combustible, by the way, and requires caution when working around) begins to break down, and the sulfuric acid begins to stick to the lead plates, leaving no place for electrons to connect with the lead. The result? No spark, no electricity – no go.
The best way to avoid this unhappy condition is just to keep the battery charged, which will preserve your battery’s life, and make it possible for you to drive out in your classic anytime.
Driving is the usual way of keeping your battery topped up, since the alternator is designed to do that, but with a seldom-used vehicle (like a classic, an RV, boat, or ATV) you have to come up with another method. You could choose a battery tender, float charger, or other device that must be connected to house current, or you could choose a solar trickle charger. If you live in an area with plenty of sun, then this could be the best solution of all, as long as you don’t keep your vehicle in a garage, where solar energy is usually very limited. Even with a car cover, you could connect a solar charger and lay it on top, to get the most power out of the sun every day. This saves on electric bills, and is a far more ecologically sound method of keeping batteries topped off.
Solar trickle chargers attach either with clips directly to the battery, with a cable long enough to run to your solar panel, which comes in many sizes, many of which fit easily into the windshield. You can also find models that connect with a cigarette lighter plug. If you’re charging a boat, a solar charger can be mounted anywhere the sun shines.
Solar chargers have the capacity to top up the charge on your 12-volt battery, which is better than a float charger or battery maintainer, for example, which will only keep the battery at the voltage it has already, and so aren’t as good for keeping your battery at the top voltage. It’s very important to remember, however, that a trickle charger of any kind will not restore a completely dead battery in any case.
More is not necessarily better – any charger, including a solar charger, has the capacity to overcharge a battery, which will shorten its life just the same as letting it go dead. If the charger has a smaller capacity, 1.5 amps, for example, overcharging is not so likely, even if the panel uses continuous charge. Larger sizes, like 5 amps or more, need a controller, which senses that a battery is filled and shuts the charger off.